Waste gas purification apparatus

Abstract

A waste gas purification apparatus having an elongated vertical hollow furnace shaft adapted to receive pebbles therein with a waste gas inlet at the lower end with a pebble discharge means at said lower end. At the top of the shaft is a narrow exhaust gas duct with a pebble feed chute, a pebble charge device and a pebble recirculating tube extending from the discharge hoppers to the charge device. A blower is coupled to the gas inlet for force feeding waste gas through said gas inlet. At the upper end of the shaft is an inactive travel zone. Between the inactive travel zone and the lower shaft is an intermediate shaft with a temperature control chamber in parallel with said intermediate shaft. Pebbles move downwards in the shaft from the inactive travel zone to the discharge hoppers and are recirculated to the upper end while waste gas is fed to the lower end and travels up through the shaft, a portion of the gas passing through the temperature control chamber, the clean gas leaving the upper end.

We claim: 
     
       1. A waste gas purification apparatus comprising in combination: (a) an elongated vertical hollow furnace shaft (2), with upper and lower ends and waste gas inlet means (7) at the lower end, said shaft being adapted to receive therein pebbles or pellets;   (b) a plurality of in series discharge hoppers (6, 18, 20) with a pebble discharge means (5, 17, 19) at said lower end;   (c) an exhaust gas duct (21) at the top of said shaft (2) said duct (21) having a lower part, a pebble feeding chute (22) coupled to said lower part, with a pebble charge device (8) and a pebble recirculating tube (23) extending from said discharge hoppers to said charge device (8);   (d) an annular waste gas supply main (24) around said lower end connected to said gas inlet means (7), blower means (25) coupled to said gas inlet means (7) for force feeding waste gas through said gas inlet means;   (e) an inactive travel zone (33) defined at said upper end having a widening section with a narrow outlet, a lower shaft (14) towards the lower end with a uniform cross-section; and,   (f) an intermediate shaft (15) between said inactive travel zone (33) and said lower shaft (14), including a temperature control chamber (11) in parallel with said intermediate shaft, branch lines (27, 28) connecting said intermediate shaft and said temperature control chamber, including damper means (13) to control the flow of gas, a dust pocket (32) in said temperature control chamber, whereby pebbles or pellets move downwards in the shaft from the inactive travel zone (33) to the discharge hoppers and are recirculated to the upper end while waste gas is fed to the lower end and travels up through the shaft, a portion of the gas passing through the temperature control chamber, the clean gas leaving the upper end.